Safety release bumper tool



Aug. 19, 1969 o. R. REARDON SAFETY RELEASE BUMPER TOOL Filed March 8, 1968.

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United States Patent 3,461,982 SAFETY RELEASE BUMPER TOOL Daniel Richard Reardon, 1L0. Box 7097, Long Beach, Calif.. 90807 Filed Mar. 8, 1968, Ser. No. 711,667 Int. Cl. E2 1b 1/10, 23/00, N04

US. Cl. 175-294 4 Claims ABSTRACT OF THE DISCLOSURE internal nut having external left hand threads screwing into the lower end of said external mandrel. An internal tubular mandrel slideably fits within said nut and has an annular external shoulder at its upper end which slideably fits within said external mandrel, and left hand external threads which screw into the internal left hand threads of said sub. The lower end of the inner mandrel connects to and supports said tail pipe during the operation of installing said packer and tail pipe in a well. Clockwise rotation of said packer mandrel when said tail pipe is stuck in the well, unscrews said inner tubular mandrel from said sub and permits telescopic extension and contraction of said bumper thereby applying jarring upward blows to said tail pipe in the effort to dislodge the same. Opposed annular faces of said nut and annular shoulder have interlocking lugs for unscrewing said nut from within said outer mandrel after said tool is fully extended as aforesaid and said packer mandrel is rotated clockwise, thereby disconnecting said packer from said tail pipe, permitting said packer and sub and external bumper mandrel to be withdrawn from the well.

Background of the invention (1) The field of invention embraces the development of tools facilitating petroleum production from deep wells, and particularly the installation of a hydraulically set production packer for packing off an oil production zone of a well bore and connecting said packer with a tail pipe extending deep into said zone, and permitting the ready recovery of said tail pipe and packer, and, in case the recovery of the tail pipe proves unfeasible, the ready separation of the tail pipe from the packer and recovery of the latter.

(2) The prior art embraces various releasable bumpers designed for this general purpose but none of these has been suitable for the particular purpose above pointed out.

Summary of the invention In using such a hydraulically set production packer, it is suspended on a tubing string which connects with the upper end of a tubular mandrel which extends downwardly through the packer and supports a tail pipe from ice tated clockwise to disengage certain left hand threads provided for axially positioning the mandrel in the packer. This allows the mandrel to be lifted rendering bypasses operative to bleed the fluid from the packer thus deflating the same for withdrawal from the well.

In the event the tail pipe has become stuck in the well, so that it can not be either rotated or lifted by manipulation of the tubing string, the present invention provides a facility which permits rotation and lifting of the tubing string to free the packer. It likewise facilitates application of a jarring action upon the tail pipe in the effort to dislodge this and, failing in this effort, offers a means operative by manipulation of the tubing string for disengaging the tail pipe from the packer whereby the latter may be readily recovered.

Brief description of the drawing FIGURE 1 is a vertical sectional view of a preferred embodiment of the present invention as this appears when it provides a connection between the lower end of a packer mandrel and the upper end of a tail pipe while running a packer assembly into a well.

FIGURE 2 is an operational view showing a lower portion of the invention with the mandrels thereof in relatively extended relation during the manipulation of the invention in the process of attempting to remove a stuck tail pipe from the Well or when separating the mandrels of the invention to disconnect the packer mandrel from the tail pipe thereby permitting the packer to be withdrawn from the well.

FIGURE 3 is a cross-sectional View taken on the line 33 of FIGURE 1 and illustrates the configuration of the lower surface of the external annular shoulder formed on the internal mandrel of the invention.

FIGURE 4 is a cross-sectional view taken on the line 4-4 of FIGURE 1 and illustrates the surface configuration of the upper end of the left hand threaded nut which is screwed into the lower end of the external mandrel of the invention and which is adapted to be unscrewed therefrom by inter-engagement between said nut and said external annular shoulder on the internal mandrel as shown in FIGURE 2.

Description of the preferred embodiment Referring specifically to the drawings, the present invention comprises a safety release bumper tool 10 which is particularly designed for use in connection with a conventional pressure seal packer 11 having a tubular mandrel 12 which is provided with external right hand threads 13 at its lower end.

Being a part of the prior art, the packer 11 will not be described in detail herein, as the description of the mode of operation of this appearing in the above summary of the invention will amply indicate the manner in which the present invention cooperates With said packer in the performance of its essential functions.

The bumper tool 10 includes an upper sub 14 having an internally threaded box 15 into which the lower end of the packer mandrel 12 screws. The sub 14 also has a downward tubular extension 16 having right hand external threads 17 and left hand internal threads 18. A short smooth counter bore 19 is provided in the lower end of extension 16.

The bumper tool 10 also includes an external tubular mandrel 20 which is internally threaded at its upper end to screw onto the right hand external threads 17 of the sub 14 while the lower end of said external mandrel is against the lower end of external mandrel 20. The upper end of nut 25 is provided with four lugs 29 and four recesses 30 which are symmetrically arranged circumferentially on said nut as shown in FIGURE 4.

The bumper tool also includes an internal tubular mandrel 31 which slideably fits the bore 27 of the nut 25 and has an external annular anvil shoulder 32 near its upper end which slideably fits within the external mandrel and is disposed in axial opposition to the hammer nut 25. The lower face of shoulder 32 is provided with four lugs 33 and four recesses 34 which are symmetrically spaced circumferentially on said shoulder so that when said shoulder is engaged by said nut as shown in FIGURE 2, the lugs 29 will fit into the recesses 34 and the lugs 33 will fit into the recesses 30. By-pass slots 35 are provided longitudinally in the periphery of external shoulder 32 for a purpose which will be made clear hereinafter.

An upper portion 40 of the mandrel 31 which is disposed above the external annular shoulder 32 has a slightly thicker wall than the balance of said mandrel and has formed thereon left hand threads 41 which screw into left hand threads 18 of the sub 14. Portion 40 has a smooth cylindrical surface 42 between said threads and external annular shoulder 32 which slideably fits counter bore 19 and has an annular groove 43 for receiving an O-ring 44 to make a fluid tight seal between internal mandrel 31 and sub 14.

The lower end of internal tubular mandrel 31 extends downwardly beneath the nut and is provided with external threads 45 which screw into a collar 46 of a tail pipe 47 which is thereby connected to and suspended from said internal tubular mandrel 31.

Operation As above noted, FIGURE 1 illustrates the invention in the condition in which it unites the lower end of the packer mandrel 12 with the tail pipe 47 as the packer 11 is being lowered into a well and throughout whatever use the packer assembly is subjected to prior to the time arriving when it becomes necessary to withdraw the packer, and if possible, also the tail pipe from the well. The first step in this removal operation involves the clockwise rotation of the packer mandrel 12 through about five turns which disengages the left hand threads within the packer uniting the mandrel and the packer against relative motion axially.

Inasmuch as the bumper tool 10 is provided especially for service in accommodating the various steps necessary to remove the packer from the well when the tail pipe 47 is stuck in the well, let us assume that this is a fact in the particular removal operation being described. With the tail pipe 47 thus stuck preventing either rotation or lengthwise movement, the internal tubular mandrel 31 which is united to said tail pipe by coupling 46 likewise stuck in said well and unresponsive to attempts to rotate or move the same vertically. Thus, the clockwise rotation of the packer mandrel 12 is rendered feasible only by the fact that the nut 25 is freely rotatable on the internal tubular mandrel 31 and the latter is connected to the sub 14 by left hand threads 41 screwing into left hand threads 18 of the sub so that clockwise rotation of sub 14 by similar rotation of packer mandrel 12 unscrews these left hand threads thereby permitting the clockwise rotation of the packer mandrel 12 necessary to disassociate this sufliciently from the packer 11 to permit the packer mandrel to be lifted after continued clockwise rotation of said packer mandrel completes the unscrewing of the left hand threads 41 of the internal mandrel 31 from the left hand threads 18 of the sub 14.

As before noted, vertical movement of the packer mandrel 12 following its being freed for such movement relative to the packer 11, renders suitable by-passes in the packer operative to bleed into the well bore above and below the packer the fluid by which the packer has been expanded so that the packer is deflated and rendered readily removable from the well when the packer mandrel 12 has been disconnected from the tail pipe 47.

With the deflating of the packer 11 and the unscrewing of the internal mandrel 31 from the sub 14, the external tubular mandrel 20 may be freely shifted vertically by raising and lowering the tubing string on which the packer mandrel 12 is mounted so that the hammer nut 25 may be employed to strike upward blows against the external annular shoulder 32 on the internal mandrel 31 with the object of dislodging the tail pipe from the well whereby said pipe may be freed and lifted with the packer 11 from the well. In the event that such jarring action is ineffective to accomplish this object, the bumper tool 10 is provided with means for disconnecting the packer from the tail pipe and thereby permit the packer and the sub 14 and the external mandrel 20 of the tool 10 to be freely withdrawn from the well. This accomplished'by lifting the packer and its mandrel 12 until the external tubular mandrel 20 of the tool 10 is positioned as shown in FIGURE 2 and then rotated so as to cause inter-engagement of the lugs and recesses 29 and 30 with the lugs and recesses 33 and 34 so as to prevent relative rotation between the nut 25 and the internal tubular mandrel 31. Clockwise rotation imparted now to the packer mandrel 12, the sub 14 and the bumper mandrel 2ft unscrews the latter mandrel from the hammer nut 25 by virtue of fact that these two elements are connected together by left hand threads. With the mandrel 20 thus separated from the hammer nut 25, said mandrel is free to be withdrawn upwardly with the packer 11 thereby salvaging all the packer assembly excepting tail pipe 47, the internal mandrel 31 and the hammer nut 25.

The by-pass slots 35 are provided in the external annular shoulder 32 to allow free passage of well fluids in which the tool It) is submerged during the bumping op erations in the effort to dislodge the tail pipe 47 so that these operations will not be unduly retarded by the close fit which said shoulder has within the external mandrel 20.

I claim:

1. A safety release bumper tool comprising an upper sub for connecting said tool to a packer mandrel, said sub having a tubular downward extension having right hand external threads and left hand internal threads.

an external tubular mandrel having internal right hand threads at its upper end screwing on the aforesaid external threads of said sub, said external mandrel having left hand internal threads at its lower end;

a tubular hammer nut having left hand external threads and screwing into the lower end of said external mandrel;

an internal tubular mandrel slideably extending through said nut and having left hand external threads at its upper end screwing into the aforesaid internal left hand threads of said sub,

an anvil shoulder means provided externally on said internal mandrel for jarring engagement by said hammer nut when said left hand threads uniting the upper end of said internal mandrel with said sub are unscrewed; and

means on the lower end of said internal mandrel for connecting the same to a tail pipe.

2. A combination as recited in claim 1 wherein interfitting lugs and recesses are provided on the meeting faces of said nut and said external shoulder for transmitting torque from said internal mandrel to said nut for holding the latter stationary during the unscrewing of said external mandrel from said nut by clockwise rotation of said external mandrel.

3. A combination as recited in claim 2 where said external shoulder means is in the form of an annulus said annulus being provided with by-pass slots through which well fluid may by-pass during relative reciprocation between said external and internal mandrels during the operation of said tool. 4 A combination as recited .in claim 3 where O-ring seal means provided on said internal tubular mandrel between said left hand threads thereof and said external annular shoulder, said means fitting into said sub counter bore making a liquid tight seal between said internal tubular mandrel and said sub. 10 175306 References Cited UNITED STATES PATENTS Barnhart et al. 175-306 Pyles 175306 Banks l75306 Berry 175306 -JAMES A. LEPPINK, Primary Examiner US. Cl. X.R. 

